<a href=showthread.php?s=&postid=8846607#post8846607 target=_blank>Originally posted</a> by llebcire
Just a few of my random thoughts...
One, with all of the concern around UV and the MH's why not just shut them down for a few days and see what happens?
Second, and more importantly, this really sounds like something made its way into your water.
I realize that it's a tough question to ask, especially of your parents, but I would need to know...
Did anything accidentally get dropped into the tank? Use the wrong container? Was there any reason that either one of them needed to put their hands in the tank? Just for an instance? Residual soap, chemicals, lotions, etc. could certainly cause this type of problem!
I hope that you get to the bottom of it!